Neurotransmitter receptor and calcium channel structure and function in airway smooth muscle will be investigated. The slow inward calcium channel will be quantitated and characterized in smooth muscle utilizing 3H-nitrendipine specific binding; the Ca++ dependence of smooth muscle contraction will be investigated together with the sensitivity of mechanical responses to "calcium channel antagonists." Adrenergic (Alpha and Beta), muscarinic, histamine and LTD4 receptors will be quantitated in the same smooth muscle preparation and related to calcium channels. Using a covalent calcium channel antagonist and channel specific monoclonal antibodies, the molecular structure of the calcium channel will be elucidated. The mechanism of action of autoantibodies from asthma patients, specific for Beta2-adrenergic receptors, will be investigated in airway smooth muscle and cultured lung cells by measuring contractile responses, cylic AMP production, Beta-receptor synthesis and turnover in methyltransferase activity. Using the antireceptor autoantibodies and Beta-receptor specific monoclonal antibodies, the airway smooth muscle Beta2 receptor will be isolated and characterized. These studies have significance to the understanding of, diagnosis and treatment of allergic respiratory disease. Implications to cardiovascular disease also exist.